<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script type="text/javascript">
        //设置函数参数默认值
        //ES5方式
        // function fn(name,age){
        //     name=name||"tom";
        //     age=age||17;
        //     console.log(name+","+age);
        // }
        // //ES5+类型检查
        // function fn2(name,age){
        //     name=(typeof name!='undefined'?name:'tom');
        //     name=(y=typeof age!='undefined'?age:17);
        //     console.log(name+","+age);
        // }

        // //ES6方式
        // function fn3(name='tom',age=17){
        //     console.log(name+","+age);
        // }

        // fn();
        // fn2();
        // fn3();

        //rest参数
        //ES5方式
        function join(){
            var str="";
            for(var i=0;i<arguments.length;i++){
                if(i==0){
                    str=arguments[i];
                }else{
                    str+="|"+arguments[i];
                }
            }
            return str;
        }
        console.log(join("hello","world"));

        //Es6
        function join2(...strs){
            var str="";
            for(var i=0;i<strs.length;i++){
                if(i==0){
                    str=strs[i];
                }else{
                    str+="|"+strs[i];
                }
            }
            return str;
        }
        console.log(join2("hello","world","你好","世界"));
    </script>
</body>
</html>